1. Field of the Invention
The present invention relates to a semiconductor device which performs data communication (reception and transmission) by wireless communication. The present invention relates to, in particular, a semiconductor device including a protection circuit which prevents element deterioration or element destruction of the semiconductor device when a large amount of electric power is received by wireless communication.
2. Description of the Related Art
Nowadays, an individual identification technology using wireless communication (hereinafter referred to as a wireless communication system) has attracted attention. In particular, as a data carrier which communicates data by wireless communication, an individual identification technology with a semiconductor device utilizing an RFID (Radio Frequency Identification) technology (also called an RFID tag, an RF tag, an IC (Integrated Circuit) tag, an IC chip, a wireless tag, or an electronic tag) has attracted attention. The semiconductor device which can perform data reception and transmission by wireless communication has started to be used for production, management, or the like of an individual object and has been developed to be applied to personal authentication.
A wireless communication system herein is a communication system which wirelessly exchanges data between a power supply source and transceiver such as a reader/writer and a transceiver such as a semiconductor device.
The wireless communication system does not need a physical connection between the reader/writer and the semiconductor device. That is, as log as the semiconductor device exists in a region specified by the reader/writer, data can be exchanged with the semiconductor device by communication between the reader/writer and the semiconductor device.
As for the reader/writer and the semiconductor device, in order to extend the communication distance therebetween, research and development for increasing the power supply efficiency from the reader/writer to the semiconductor device has been activated (e.g., reference 1: Japanese Published Patent Application No. 2006-5651).